PROJECT SUMMARY The Design/Statistics Core (DSC) will be an indispensable component of the National Institute of Aging (NIA) Alzheimer's disease (AD)/AD-related dementia (AD/ADRD) Healthcare Systems (HCS) Collaboratory. It will work with other Collaboratory Work Group Cores and Teams to develop knowledge and provide guidance to conduct rigorous embedded pragmatic clinical trials (ePCTs) to improve the care and health outcomes of persons with dementia (PWD) and their caregivers (CGs). It will serve as a national resource providing biostatistical expertise to Collaboratory-supported pilot studies, career development awardees (CDAs), and other NIA-funded investigators conducting such trials. The DSC will contribute to all aspects of the design, conduct, and analysis of these projects, and will develop novel statistical methodology for the design and analysis of ePCTs conducted among PWD within HCS. To advance this field and create a durable knowledge repository, the Design/Statistics Core will provide guidance in areas such as: 1) robust design of ePCTs, 2) statistical analysis of ePCTs, 3) methods for handling missing data, contamination, and other irregularities, 4) strategies for dealing with pitfalls of specific relevance to AD/ADRD, 5) replicability and reproducibility, 6) multiplicity and multiple comparisons, 7) consideration of under-represented minorities and important subgroups, including treatment of sex as a biological variable, 8) documentation and dissemination of software and analytic code, 9) publication and dissemination, and 10) training and mentoring of junior quantitative scientists and clinical investigators. The Design/Statistics Core?s other main function will be to provide consultation and services to the AD/ADRD Collaboratory as a whole and particularly to the pilot studies, career, CDA recipients, and other NIA-funded investigators. The work of the DSC will be enabled by the leadership of Dr. Heather Allore PhD, Professor of Medicine in the Yale School of Medicine, and Professor of Biostatistics at the Yale School of Public Health, and Director of the Yale Alzheimer's Disease Research Center's Data Management and Statistics Core. She is an experienced trialist and founder of the field of Gerontological Biostatistics. Dr. Allore will be joined by a team of six exceptional Executive Committee members who bring varied expertise in AD/ARDR research, aging research, cluster randomized trials, and the conduct of ePCTs in older persons. The DSC?s Aims are: Aim 1: To provide biostatistical assistance and guidance to Collaboratory pilot studies, CDAs recipients and NIA-funded investigators planning or conducting ePCTs in PWD and CG; Aim 2: To develop novel biostatistical approaches, and create and disseminate guidance documents and products relevant to the design and conduct of ePCTs in PWD with HCS, Aim 3: To work with the Technical/Data Core, to establish and manage access to and sharing of administrative data (e.g., electronic health records, claims data) for use by AD/ADRD Collaboratory investigators (e.g. pilot project leaders), in providing guidance on reproducible analyses and replication studies.